The default is likely wrong.
Out of all the callees, only a single one needs to pass-in false (JumpThread),
everything else either already passes true, or should pass true.
Until the default is flipped, at least make it harder to unintentionally
add new callees with UseBlockValue=false.
"Does the predicate hold between two ranges?"
Not very surprisingly, some places were already doing this check,
without explicitly naming the algorithm, cleanup them all.
"Does the predicate hold between two ranges?"
Not very surprisingly, some places were already doing this check,
without explicitly naming the algorithm, cleanup them all.
This patch updates the linkage name in the DISubprogram of coro-split
functions, which is particularly important for Swift, where the
funclets have a special name mangling. This patch does not affect C++
coroutines, since the DW_AT_specification is expected to hold the
(original) linkage name. I believe this is mostly due to limitations
in AsmPrinter, so we might be able to relax this restriction in the
future.
Differential Revision: https://reviews.llvm.org/D99693
As suggested in the review thread for 5094e12 and seen in the
motivating example from https://llvm.org/PR49885, it's not
clear if we have a way to create the optimal code without
this heuristic.
Add an ability to store `Offset` between partially aliased location. Use this
storage within returned `ResultAlias` instead of caching it in `AAQueryInfo`.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D98718
Main reason is preparation to transform AliasResult to class that contains
offset for PartialAlias case.
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D98027
Previously loading the vtable used in calling a virtual method in a loop
was not hoisted out of the loop. This fixes that.
canSinkOrHoistInst() itself doesn't check that the load operands are
loop invariant, callers also check that separately.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D99784
meetBDVState looks pretty difficult to read and follow.
This is purely NFC but doing several things:
1) Combine meet and meetBDVState
2) Move the function to be a member of BDVState
3) Make BDVState be a mutable object
4) Convert switch to sequence of ifs
5) Adds comments.
Reviewers: reames, dantrushin
Reviewed By: reames
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D99064
Pretty straightforward use of existing infrastructure and port of the attributor inference rules for nosync.
A couple points of interest:
* I deliberately switched from "monotonic or better" to "unordered or better". This is simply me being conservative and is better in line with the rest of the optimizer. We treat monotonic conservatively pretty much everywhere.
* The operand bundle test change is suspicious. It looks like we might have missed something here, but if so, it's an issue with the existing nofree inference as well. I'm going to take a closer look at that separately.
* I needed to keep the previous inference from readnone. This surprised me, but made sense once I realized readonly inference goes to lengths to reason about local vs non-local memory and that writes to local memory are okay. This is fine for the purpose of nosync, but would e.g. prevent us from inferring nofree from readnone - which is slightly surprising.
Differential Revision: https://reviews.llvm.org/D99769
This fixes a "Cached first special instruction is wrong!" assert.
The assert fires because replacing a value with another can cause an
instruction to no longer be "special" to ICF. In this case,
devirtualization happened, turning an indirect call to a
call to a willreturn function which is no longer special.
Reviewed By: nikic, rnk
Differential Revision: https://reviews.llvm.org/D99977
After D99249 we use three different loop pass managers for LICM,
LoopRotate and LICM+LoopUnswitch. This happens because LazyBFI
and LazyBPI are not preserved by LoopRotate (note that D74640
is no longer needed). Avoid this by marking them as preserved.
My understanding of D86156 is that it is okay to simply preserve
them (which LoopUnswitch already does for the same reason) and
rely on callbacks to deal with deleted blocks.
Differential Revision: https://reviews.llvm.org/D99843
After loop interchange, the (old) outer loop header should not jump to
the `LoopExit`. Note that the old outer loop becomes the new inner loop
after interchange. If we branched to `LoopExit` then after interchange
we would jump directly from the (new) inner loop header to `LoopExit`
without executing the rest of outer loop.
This patch modifies adjustLoopBranches() such that the old outer
loop header (which becomes the new inner loop header) jumps to the
old inner loop latch which becomes the new outer loop latch after
interchange.
Reviewed By: bmahjour
Differential Revision: https://reviews.llvm.org/D98475
Instead of passing the start value and the defined value to
widenPHIInstruction, pass the VPWidenPHIRecipe directly, which can be
used to get both (and more in future patches).
During LoopStrengthReduce, some of the SSA values that are used by debug values
may be lost and/or salvaged. After LSR we attempt to recover any undef debug
values, including any that were salvaged but then lost their values afterwards,
by replacing the lost values with any live equal values (plus a possible
constant offset) that have been gathered prior to running LSR. When we do this
we restore the debug value's original DIExpression, to undo any salvaging (as we
have gone back to using the original debug value).
This process can currently produce invalid debug info if the number of operands
has changed by salvaging during LSR. Replacing old values during the
applyEqualValues step does not change the number of location operands, which
means that when we restore the old DIExpression we may have a mismatch between
the number of operands used by the debug value and the number of operands
referenced by the DIExpression. This patch fixes this by restoring the full
original location metadata at the start of the applyEqualValues step, so that
there is no mismatch in operand count between the debug value and its
DIExpression.
Differential Revision: https://reviews.llvm.org/D98644
D99674 stopped the folding of certain select operations into and/or, due
to incorrect folding in the presence of poison. D97360 added some costs
to attempt to account for the change, but only worked at the getUserCost
level, not the getCmpSelInstrCost that the vectorizer will use directly.
This adds similar logic into the vectorizer to handle these logical
and/or selects, treating them like and/or directly.
This fixes 60% performance regressions from code like the attached test
case.
Differential Revision: https://reviews.llvm.org/D99884
After loop interchange, the (old) outer loop header should not jump to
`LoopExit`. Note that the old outer loop becomes the new inner loop
after interchange. If we branched to `LoopExit` then after interchange
we would jump directly from the (new) inner loop header to `LoopExit`
without executing the rest of (new) outer loop.
This patch modifies adjustLoopBranches() such that the old outer
loop header (which becomes the new inner loop header) jumps to the
old inner loop latch which becomes the new outer loop latch after
interchange.
Reviewed By: bmahjour
Differential Revision: https://reviews.llvm.org/D98475
-Make sure of the CreateShl/LShr/AShr methods that take a uint64_t
instead of creating a ConstantInt for 1 ourselves.
-Use Builder.getInt1 or ConstantInt::getBool instead of a conditional.
-Pull out repeated calls to getType.
All of the code that handles general constant here (other than the more
restrictive APInt-dealing code) expects that it is an immediate,
because otherwise we won't actually fold the constants, and increase
instruction count. And it isn't obvious why we'd be okay with
increasing the number of constant expressions,
those still will have to be run..
But after 2829094a8e
this could also cause endless combine loops.
So actually properly restrict this code to immediates.
This fixes the examples from
D99674 and
https://llvm.org/PR49878
The matchers succeed on partial undef/poison vector constants,
but the transform creates a full 'not' (-1) constant, so it
would undo a demanded vector elements change triggered by the
extractelement.
Differential Revision: https://reviews.llvm.org/D100044
We see a regression related to low probe factor(0.01) which prevents some callsites being promoted in ICPPass and later cause the missing inline in CGSCC inliner. The root cause is due to redundant(the second) multiplication of the probe factor and this change try to fix it.
`Sum` does multiply a factor right after findCallSamples but later when using as the parameter in setProbeDistributionFactor, it multiplies one again.
This change could get ~2% perf back on mcf benchmark. In mcf, previously the corresponding factor is 1 and it's the recent feature introducing the <1 factor then trigger this bug.
Reviewed By: hoy, wenlei
Differential Revision: https://reviews.llvm.org/D99787
No need to lookup through and/or try to vectorize operands of the
CmpInst instructions during attempts to find/vectorize min/max
reductions. Compiler implements postanalysis of the CmpInsts so we can
skip extra attempts in tryToVectorizeHorReductionOrInstOperands and save
compile time.
Differential Revision: https://reviews.llvm.org/D99950
The swap of the operands can affect later transforms that
are expecting a constant as operand 1. I don't think we
can trigger a bug with the current code, but I hit that
problem while drafting a new transform for min/max intrinsics.
This reverts commit a547b4e26b,
relanding commit 31d219d299,
which was reverted because there was a conflicting inverse transform,
which was causing an endless combine loop, which has now been adjusted.
Original commit message:
https://alive2.llvm.org/ce/z/67w-wQ
We prefer `add`s over `sub`, and this particular xform
allows further folds to happen:
Fixes https://bugs.llvm.org/show_bug.cgi?id=49858
I.e., if any/all of the consants is an expression, don't do it.
Since those constants won't reduce into an immediate,
but would be left as an constant expression, they could cause
endless combine loops after 31d219d299
added an inverse transformation.
Summary:
The function SplitCriticalEdge (called by SplitEdge) can return a nullptr in
cases where the edge is a critical. SplitEdge uses SplitCriticalEdge assuming it
can always split all critical edges, which is an incorrect assumption.
The three cases where the function SplitCriticalEdge will return a nullptr is:
1. DestBB is an exception block
2. Options.IgnoreUnreachableDests is set to true and
isa(DestBB->getFirstNonPHIOrDbgOrLifetime()) is not equal to a nullptr
3. LoopSimplify form must be preserved (Options.PreserveLoopSimplify is true)
and it cannot be maintained for a loop due to indirect branches
For each of these situations they are handled in the following way:
1. Modified the function ehAwareSplitEdge originally from
llvm/lib/Transforms/Coroutines/CoroFrame.cpp to handle the cases when the DestBB
is an exception block. This function is called directly in SplitEdge.
SplitEdge does not call SplitCriticalEdge in this case
2. Options.IgnoreUnreachableDests is set to false by default, so this situation
does not apply.
3. Return a nullptr in this situation since the SplitCriticalEdge also returned
nullptr. Nothing we can do in this case.
Reviewed By: asbirlea
Differential Revision:https://reviews.llvm.org/D94619
Follow up to a6d2a8d6f5. These were found by simply grepping for "::assume", and are the subset of that result which looked cleaner to me using the isa/dyn_cast patterns.
Follow up to a6d2a8d6f5. This covers all the public interfaces of the bundle related code. I tried to cleanup the internals where the changes were obvious, but there's definitely more room for improvement.
Fixes the ASan RISC-V memory mapping (originally introduced by D87580 and
D87581). This should be an improvement both in terms of first principles
soundness and observed test failures --- test failures would occur
non-deterministically depending on the ASLR random offset.
On RISC-V Linux (64-bit), `TASK_UNMAPPED_BASE` is currently defined as
`PAGE_ALIGN(TASK_SIZE / 3)`. The non-power-of-two divisor makes the result
be the not very round number 0x1555556000. That address had to be further
rounded to ensure page alignment after the shadow scale shifting is applied.
Still, that value explains why the mapping table may look less regular than
expected.
Further cleanups:
- Moved the mapping table comment, to ensure that the two Linux/AArch64
tables stayed together;
- Removed mention of Sv48. Neither the original mapping nor this one are
compatible with an actual Linux Sv48 address space (mainline Linux still
operates Sv48 in Sv39 mode). A future patch can improve this;
- Removed the additional comments, for consistency.
Differential Revision: https://reviews.llvm.org/D97646
Add the subclass, update a few places which check for the intrinsic to use idiomatic dyn_cast, and update the public interface of AssumptionCache to use the new class. A follow up change will do the same for the newer assumption query/bundle mechanisms.
performScalarPREInsertion() inserts instructions into blocks that we
need to tell ImplicitControlFlowTracking about, otherwise the ICF cache
may be invalid.
Fixes PR49193.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D99909
The key change (4f5e92c) to switch gc.result and gc.relocate to being readnone landed nearly two weeks ago, and we haven't seen any fallout. Time to remove the code added to make reverting easy.
Previously we could only vectorize FP reductions if fast math was enabled, as this allows us to
reorder FP operations. However, it may still be beneficial to vectorize the loop by moving
the reduction inside the vectorized loop and making sure that the scalar reduction value
be an input to the horizontal reduction, e.g:
%phi = phi float [ 0.0, %entry ], [ %reduction, %vector_body ]
%load = load <8 x float>
%reduction = call float @llvm.vector.reduce.fadd.v8f32(float %phi, <8 x float> %load)
This patch adds a new flag (IsOrdered) to RecurrenceDescriptor and makes use of the changes added
by D75069 as much as possible, which already teaches the vectorizer about in-loop reductions.
For now in-order reduction support is off by default and controlled with the `-enable-strict-reductions` flag.
Reviewed By: david-arm
Differential Revision: https://reviews.llvm.org/D98435
Problem:
On SystemZ we need to open text files in text mode. On Windows, files opened in text mode adds a CRLF '\r\n' which may not be desirable.
Solution:
This patch adds two new flags
- OF_CRLF which indicates that CRLF translation is used.
- OF_TextWithCRLF = OF_Text | OF_CRLF indicates that the file is text and uses CRLF translation.
Developers should now use either the OF_Text or OF_TextWithCRLF for text files and OF_None for binary files. If the developer doesn't want carriage returns on Windows, they should use OF_Text, if they do want carriage returns on Windows, they should use OF_TextWithCRLF.
So this is the behaviour per platform with my patch:
z/OS:
OF_None: open in binary mode
OF_Text : open in text mode
OF_TextWithCRLF: open in text mode
Windows:
OF_None: open file with no carriage return
OF_Text: open file with no carriage return
OF_TextWithCRLF: open file with carriage return
The Major change is in llvm/lib/Support/Windows/Path.inc to only set text mode if the OF_CRLF is set.
```
if (Flags & OF_CRLF)
CrtOpenFlags |= _O_TEXT;
```
These following files are the ones that still use OF_Text which I left unchanged. I modified all these except raw_ostream.cpp in recent patches so I know these were previously in Binary mode on Windows.
./llvm/lib/Support/raw_ostream.cpp
./llvm/lib/TableGen/Main.cpp
./llvm/tools/dsymutil/DwarfLinkerForBinary.cpp
./llvm/unittests/Support/Path.cpp
./clang/lib/StaticAnalyzer/Core/HTMLDiagnostics.cpp
./clang/lib/Frontend/CompilerInstance.cpp
./clang/lib/Driver/Driver.cpp
./clang/lib/Driver/ToolChains/Clang.cpp
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99426
Changes getRecurrenceIdentity to always return a neutral value of -0.0 for FAdd.
Reviewed By: dmgreen, spatel
Differential Revision: https://reviews.llvm.org/D98963
For VPWidenPHIRecipes that model all incoming values as VPValue
operands, print those operands instead of printing the original PHI.
D99294 updates recipes of reduction PHIs to use the VPValue for the
incoming value from the loop backedge, making use of this new printing.
This patch enhances hasAddressTaken() to ignore bitcasts as a
callee in callbase instruction. Such bitcast usage doesn't really take
the address in a useful meaningful way.
Reviewed By: rampitec
Differential Revision: https://reviews.llvm.org/D98884
When we are able to SROA an alloca, we know all uses of it, meaning we
don't have to preserve the invariant group intrinsics and metadata.
It's possible that we could lose information regarding redundant
loads/stores, but that's unlikely to have any real impact since right
now the only user is Clang and vtables.
Reviewed By: rnk
Differential Revision: https://reviews.llvm.org/D99760
As shown in the example based on:
https://llvm.org/PR49832
...and the existing test, we can't substitute
a vector value because the equality compare
replacement that we are attempting requires
that the comparison is true for the entire
value. Vector select can be partly true/false.
During vectorization better to postpone the vectorization of the CmpInst
instructions till the end of the basic block. Otherwise we may vectorize
it too early and may miss some vectorization patterns, like reductions.
Reworked part of D57059
Differential Revision: https://reviews.llvm.org/D99796
This is identical to 781d077afb,
but for the other function.
For certain shift amount bit widths, we must first ensure that adding
shift amounts is safe, that the sum won't have an unsigned overflow.
Fixes https://bugs.llvm.org/show_bug.cgi?id=49778
This is discussed in https://llvm.org/PR48999 ,
but it does not solve that request.
The difference in the vector test shows that some
other logic transform is limited to scalar types.
When converting a switch with two cases and a default into a
select, also handle the denegerate case where two cases have the
same value.
Generate this case directly as
%or = or i1 %cmp1, %cmp2
%res = select i1 %or, i32 %val, i32 %default
rather than
%sel1 = select i1 %cmp1, i32 %val, i32 %default
%res = select i1 %cmp2, i32 %val, i32 %sel1
as InstCombine is going to canonicalize to the former anyway.
This patch fixes llvm.org/pr49688 by conditionally folding select i1 into and/or:
```
select cond, cond2, false
->
and cond, cond2
```
This is not safe if cond2 is poison whereas cond isn’t.
Unconditionally disabling this transformation affects later pipelines that depend on and/or i1s.
To minimize its impact, this patch conservatively checks whether cond2 is an instruction that
creates a poison or its operand creates a poison.
This approach is similar to what InstSimplify's SimplifyWithOpReplaced is doing.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D99674
When run under valgrind, or with a malloc that poisons freed memory,
this can lead to segfaults or other problems.
To avoid modifying the AdditionalUsers DenseMap while still iterating,
save the instructions to be notified in a separate SmallPtrSet, and use
this to later call OperandChangedState on each instruction.
Fixes PR49582.
Reviewed By: fhahn
Differential Revision: https://reviews.llvm.org/D98602
This patch moves mapping of IR operands to VPValues out of
tryToCreateWidenRecipe. This allows using existing VPValue operands when
widening recipes directly, which will be introduced in future patches.
The safepoints being inserted exists to free memory, or coordinate with another thread to do so. Thus, we must strip any inferred attributes and reinfer them after the lowering.
I'm not aware of any active miscompiles caused by this, but since I'm working on strengthening inference of both and leveraging them in the optimization decisions, I figured a bit of future proofing was warranted.
The ultimate reduction node may have multiple uses, but if the ultimate
reduction is min/max reduction and based on SelectInstruction, the
condition of this select instruction must have only single use.
Differential Revision: https://reviews.llvm.org/D99753
The motivation for this patch is to better estimate the cost of
extracelement instructions in cases were they are going to be free,
because the source vector can be used directly.
A simple example is
%v1.lane.0 = extractelement <2 x double> %v.1, i32 0
%v1.lane.1 = extractelement <2 x double> %v.1, i32 1
%a.lane.0 = fmul double %v1.lane.0, %x
%a.lane.1 = fmul double %v1.lane.1, %y
Currently we only consider the extracts free, if there are no other
users.
In this particular case, on AArch64 which can fit <2 x double> in a
vector register, the extracts should be free, independently of other
users, because the source vector of the extracts will be in a vector
register directly, so it should be free to use the vector directly.
The SLP vectorized version of noop_extracts_9_lanes is 30%-50% faster on
certain AArch64 CPUs.
It looks like this does not impact any code in
SPEC2000/SPEC2006/MultiSource both on X86 and AArch64 with -O3 -flto.
This originally regressed after D80773, so if there's a better
alternative to explore, I'd be more than happy to do that.
Reviewed By: ABataev
Differential Revision: https://reviews.llvm.org/D99719
Support reassociation for min/max. With that we should be able to transform min(min(a, b), c) -> min(min(a, c), b) if min(a, c) is already available.
Reviewed By: mkazantsev, lebedev.ri
Differential Revision: https://reviews.llvm.org/D88287
This is a patch to fix the bug in alignment calculation (see https://reviews.llvm.org/D90529#2619492).
Consider this code:
```
call void @llvm.assume(i1 true) ["align"(i32* %a, i32 32, i32 28)]
%arrayidx = getelementptr inbounds i32, i32* %a, i64 -1
; aligment of %arrayidx?
```
The llvm.assume guarantees that `%a - 28` is 32-bytes aligned, meaning that `%a` is 32k + 28 for some k.
Therefore `a - 4` cannot be 32-bytes aligned but the existing code was calculating the pointer as 32-bytes aligned.
The reason why this happened is as follows.
`DiffSCEV` stores `%arrayidx - %a` which is -4.
`OffSCEV` stores the offset value of “align”, which is 28.
`DiffSCEV` + `OffSCEV` = 24 should be used for `a - 4`'s offset from 32k, but `DiffSCEV` - `OffSCEV` = 32 was being used instead.
Reviewed By: Tyker
Differential Revision: https://reviews.llvm.org/D98759
The code is assuming that having an exact exit count for the loop implies that exit counts for every exit are known. This used to be true, but when we added handling for dead exits we broke this invariant. The new invariant is that an exact loop count implies that any exits non trivially dead have exit counts.
We could have fixed this by either a) explicitly checking for a dead exit, or b) just testing for SCEVCouldNotCompute. I chose the second as it was simpler.
(Debugging this took longer than it should have since I'd mistyped the original assert and it wasn't checking what it was meant to...)
p.s. Sorry for the lack of test case. Getting things into a state to actually hit this is difficult and fragile. The original repro involves loop-deletion leaving SCEV in a slightly inprecise state which lets us bypass other transforms in IndVarSimplify on the way to this one. All of my attempts to separate it into a standalone test failed.
This implements the most basic possible nosync inference. The choice of inference rule is taken from the comments in attributor and the discussion on the review of the change which introduced the nosync attribute (0626367202).
This is deliberately minimal. As noted in code comments, I do plan to add a more robust inference which actually scans the function IR directly, but a) I need to do some refactoring of the attributor code to use common interfaces, and b) I wanted to get something in. I also wanted to minimize the "interesting" analysis discussion since that's time intensive.
Context: This combines with existing nofree attribute inference to help prove dereferenceability in the ongoing deref-at-point semantics work.
Differential Revision: https://reviews.llvm.org/D99749
We have this logic duplicated in several cases, none of which were exhaustive. Consolidate it in one place.
I don't believe this actually impacts behavior of the callers. I think they all filter their inputs such that their partial implementations were correct. If not, this might be fixing a cornercase bug.
1. Need to cleanup InstrElementSize map for each new tree, otherwise might
use sizes from the previous run of the vectorization attempt.
2. No need to include into analysis the instructions from the different basic
blocks to save compile time.
Differential Revision: https://reviews.llvm.org/D99677
Removes CFGAnalyses from the preserved analyses set
returned by LoopFlattenPass::run().
Reviewed By: Dave Green, Ta-Wei Tu
Differential Revision: https://reviews.llvm.org/D99700
Name GVN uses name 'LI' for two different unrelated things:
LoadInst and LoopInfo. This patch relates the variables with
former meaning into 'Load' to disambiguate the code.
Before this change, the `llvm.access.group` metadata was dropped
when moving a load instruction in GVN. This prevents vectorizing
a C/C++ loop with `#pragma clang loop vectorize(assume_safety)`.
This change propagates the metadata as well as other metadata if
it is safe (the move-destination basic block and source basic
block belong to the same loop).
Differential Revision: https://reviews.llvm.org/D93503
This commit adjusts the order of two swappable if statements to
make code cleaner.
Reviewed By: lattner, nikic
Differential Revision: https://reviews.llvm.org/D99648
Use SetVector instead of SmallPtrSet to track values with uniform use. Doing this
can help avoid non-determinism caused by iterating over unordered containers.
This bug was found with reverse iteration turning on,
--extra-llvm-cmake-variables="-DLLVM_REVERSE_ITERATION=ON".
Failing LLVM test consecutive-ptr-uniforms.ll .
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99549
This marks FSIN and other operations to EXPAND for scalable
vectors, so that they are not assumed to be legal by the cost-model.
Depends on D97470
Reviewed By: dmgreen, paulwalker-arm
Differential Revision: https://reviews.llvm.org/D97471
Summary: Try to insert dbg.declare to entry.resume basic block in resume
function. In this way, we could print alloca such as __promise in
gdb/lldb under O2, which would be beneficial to debug coroutine program.
Test Plan: check-llvm
Reviewed by: aprantl
Differential Revision: https://reviews.llvm.org/D96938
Use SetVector instead of SmallPtrSet for external definitions created for VPlan.
Doing this can help avoid non-determinism caused by iterating over unordered containers.
This bug was found with reverse iteration turning on,
--extra-llvm-cmake-variables="-DLLVM_REVERSE_ITERATION=ON".
Failing LLVM-Unit test VPRecipeTest.dump.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D99544
Currently prof metadata with branch counts is added only for BranchInst and SwitchInst, but not for IndirectBrInst. As a result, BPI/BFI make incorrect inferences for indirect branches, which can be very hot.
This diff adds metadata for IndirectBrInst, in addition to BranchInst and SwitchInst.
Reviewed By: wmi, wenlei
Differential Revision: https://reviews.llvm.org/D99550
Use profiled call edges to augment the top-down order. There are cases that the top-down order computed based on the static call graph doesn't reflect real execution order. For example:
1. Incomplete static call graph due to unknown indirect call targets. Adjusting the order by considering indirect call edges from the profile can enable the inlining of indirect call targets by allowing the caller processed before them.
2. Mutual call edges in an SCC. The static processing order computed for an SCC may not reflect the call contexts in the context-sensitive profile, thus may cause potential inlining to be overlooked. The function order in one SCC is being adjusted to a top-down order based on the profile to favor more inlining.
3. Transitive indirect call edges due to inlining. When a callee function is inlined into into a caller function in LTO prelink, every call edge originated from the callee will be transferred to the caller. If any of the transferred edges is indirect, the original profiled indirect edge, even if considered, would not enforce a top-down order from the caller to the potential indirect call target in LTO postlink since the inlined callee is gone from the static call graph.
4. #3 can happen even for direct call targets, due to functions defined in header files. Header functions, when included into source files, are defined multiple times but only one definition survives due to ODR. Therefore, the LTO prelink inlining done on those dropped definitions can be useless based on a local file scope. More importantly, the inlinee, once fully inlined to a to-be-dropped inliner, will have no profile to consume when its outlined version is compiled. This can lead to a profile-less prelink compilation for the outlined version of the inlinee function which may be called from external modules. while this isn't easy to fix, we rely on the postlink AutoFDO pipeline to optimize the inlinee. Since the survived copy of the inliner (defined in headers) can be inlined in its local scope in prelink, it may not exist in the merged IR in postlink, and we'll need the profiled call edges to enforce a top-down order for the rest of the functions.
Considering those cases, a profiled call graph completely independent of the static call graph is constructed based on profile data, where function objects are not even needed to handle case #3 and case 4.
I'm seeing an average 0.4% perf win out of SPEC2017. For certain benchmark such as Xalanbmk and GCC, the win is bigger, above 2%.
The change is an enhancement to https://reviews.llvm.org/D95988.
Reviewed By: wmi, wenlei
Differential Revision: https://reviews.llvm.org/D99351
This fixes the miscompilation reported in https://reviews.llvm.org/rG5bb38e84d3d0#986154 .
`select _, true, false` matches both m_LogicalAnd and m_LogicalOr, making later
transformations confused.
Simplify the branch condition to not have the form.
This patch adds support for the vectorization of induction variables when
using scalable vectors, which required the following changes:
1. Removed assert from InnerLoopVectorizer::getStepVector.
2. Modified InnerLoopVectorizer::createVectorIntOrFpInductionPHI to use
a runtime determined value for VF and removed an assert.
3. Modified InnerLoopVectorizer::buildScalarSteps to work for scalable
vectors. I did this by calculating the full vector value for each Part
of the unroll factor (UF) and caching this in the VP state. This means
that we are always able to extract an arbitrary element from the vector
if necessary. In addition to this, I also permitted the caching of the
individual lane values themselves for the known minimum number of elements
in the same way we do for fixed width vectors. This is a further
optimisation that improves the code quality since it avoids unnecessary
extractelement operations when extracting the first lane.
4. Added an assert to InnerLoopVectorizer::widenPHIInstruction, since while
testing some code paths I noticed this is currently broken for scalable
vectors.
Various tests to support different cases have been added here:
Transforms/LoopVectorize/AArch64/sve-inductions.ll
Differential Revision: https://reviews.llvm.org/D98715
Use SmallVector instead of SmallSet to track the context profiles mapped. Doing this
can help avoid non-determinism caused by iterating over unordered containers.
This bug was found with reverse iteration turning on,
--extra-llvm-cmake-variables="-DLLVM_REVERSE_ITERATION=ON".
Failing LLVM test profile-context-tracker-debug.ll .
Reviewed By: MaskRay, wenlei
Differential Revision: https://reviews.llvm.org/D99547
Lookup tables generate non PIC-friendly code, which requires dynamic relocation as described in:
https://bugs.llvm.org/show_bug.cgi?id=45244
This patch adds a new pass that converts lookup tables to relative lookup tables to make them PIC-friendly.
Differential Revision: https://reviews.llvm.org/D94355
This change sets up a framework in llvm-profgen to estimate inline decision and adjust context-sensitive profile based on that. We call it a global pre-inliner in llvm-profgen.
It will serve two purposes:
1) Since context profile for not inlined context will be merged into base profile, if we estimate a context will not be inlined, we can merge the context profile in the output to save profile size.
2) For thinLTO, when a context involving functions from different modules is not inined, we can't merge functions profiles across modules, leading to suboptimal post-inline count quality. By estimating some inline decisions, we would be able to adjust/merge context profiles beforehand as a mitigation.
Compiler inline heuristic uses inline cost which is not available in llvm-profgen. But since inline cost is closely related to size, we could get an estimate through function size from debug info. Because the size we have in llvm-profgen is the final size, it could also be more accurate than the inline cost estimation in the compiler.
This change only has the framework, with a few TODOs left for follow up patches for a complete implementation:
1) We need to retrieve size for funciton//inlinee from debug info for inlining estimation. Currently we use number of samples in a profile as place holder for size estimation.
2) Currently the thresholds are using the values used by sample loader inliner. But they need to be tuned since the size here is fully optimized machine code size, instead of inline cost based on not yet fully optimized IR.
Differential Revision: https://reviews.llvm.org/D99146
Re-apply 25fbe803d4, with a small update to emit the right remark
class.
Original message:
[LV] Move runtime pointer size check to LVP::plan().
This removes the need for the remaining doesNotMeet check and instead
directly checks if there are too many runtime checks for vectorization
in the planner.
A subsequent patch will adjust the logic used to decide whether to
vectorize with runtime to consider their cost more accurately.
Reviewed By: lebedev.ri
This is a 2nd try of:
3c8473ba53
which was reverted at:
a26312f9d4
because of crashing.
This version includes extra code and tests to avoid the known
crashing examples as discussed in PR49730.
Original commit message:
As noted in D98152, we need to patch SLP to avoid regressions when
we start canonicalizing to integer min/max intrinsics.
Most of the real work to make this possible was in:
7202f47508
Differential Revision: https://reviews.llvm.org/D98981
This removes the need for the remaining doesNotMeet check and instead
directly checks if there are too many runtime checks for vectorization
in the planner.
A subsequent patch will adjust the logic used to decide whether to
vectorize with runtime to consider their cost more accurately.
Reviewed By: lebedev.ri
Differential Revision: https://reviews.llvm.org/D98634
Using $ breaks demangling of the symbols. For example,
$ c++filt _Z3foov\$123
_Z3foov$123
This causes problems for developers who would like to see nice stack traces
etc., but also for automatic crash tracking systems which try to organize
crashes based on the stack traces.
Instead, use the period as suffix separator, since Itanium demanglers normally
ignore such suffixes:
$ c++filt _Z3foov.123
foo() [clone .123]
This is already done in some places; try to do it everywhere.
Differential revision: https://reviews.llvm.org/D97484
I think byval/sret and the others are close to being able to rip out
the code to support the missing type case. A lot of this code is
shared with inalloca, so catch this up to the others so that can
happen.
This is a small patch to make FoldBranchToCommonDest poison-safe by default.
After fc3f0c9c, only two syntactic changes are needed to fix unit tests.
This does not cause any assembly difference in testsuite as well (-O3, X86-64 Manjaro).
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D99452
During context promotion, intermediate nodes that are on a call path but do not come with a profile can be promoted together with their parent nodes. Do not print sample context string for such nodes since they do not have profile.
Reviewed By: wenlei
Differential Revision: https://reviews.llvm.org/D99441
This reverts commit 3c8473ba53 and includes test diffs to
maintain testing status.
There's at least 1 place that was not updated with 7202f47508 ,
so we can crash mismatching select and intrinsics as shown in
PR49730.
This patch simplifies the calculation of certain costs in
getInstructionCost when isScalarAfterVectorization() returns a true value.
There are a few places where we multiply a cost by a number N, i.e.
unsigned N = isScalarAfterVectorization(I, VF) ? VF.getKnownMinValue() : 1;
return N * TTI.getArithmeticInstrCost(...
After some investigation it seems that there are only these cases that occur
in practice:
1. VF is a scalar, in which case N = 1.
2. VF is a vector. We can only get here if: a) the instruction is a
GEP/bitcast with scalar uses, or b) this is an update to an induction variable
that remains scalar.
I have changed the code so that N is assumed to always be 1. For GEPs
the cost is always 0, since this is calculated later on as part of the
load/store cost. For all other cases I have added an assert that none of the
users needs scalarising, which didn't fire in any unit tests.
Only one test required fixing and I believe the original cost for the scalar
add instruction to have been wrong, since only one copy remains after
vectorisation.
Differential Revision: https://reviews.llvm.org/D98512
When prioritize call site to consider for inlining in sample loader, use number of samples as a first tier breaker before using name/guid comparison. This would favor smaller functions when hotness is the same (from the same block). We could try to retrieve accurate function size if this turns out to be more important.
Differential Revision: https://reviews.llvm.org/D99370
In DeadArgumentElimination pass, if a function's argument is never used, corresponding caller's parameter can be changed to undef. If the param/arg has attribute noundef or other related attributes, LLVM LangRef(https://llvm.org/docs/LangRef.html#parameter-attributes) says its behavior is undefined. SimplifyCFG(D97244) takes advantage of this behavior and does bad transformation on valid code.
To avoid this undefined behavior when change caller's parameter to undef, this patch removes noundef attribute and other attributes imply noundef on param/arg.
Differential Revision: https://reviews.llvm.org/D98899
This *only* changes the cases where we *really* don't care
about the iteration order of the underlying contained,
namely when we will use the values from it to form DTU updates.
The SCEV commit b46c085d2b [NFCI] SCEVExpander:
emit intrinsics for integral {u,s}{min,max} SCEV expressions
seems to reveal a new crash in SLPVectorizer.
SLP crashes expecting a SelectInst as an externally used value
but umin() call is found.
The patch relaxes the assumption to make the IR flag propagation safe.
Reviewed By: spatel
Differential Revision: https://reviews.llvm.org/D99328
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses. This should enable
easier experimentation with HWASan on x86_64 platforms.
Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.
Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes. This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98875
We do not need to scan further if the upper end or lower end of the
basic block is reached already and the instruction is not found. It
means that the instruction is definitely in the lower part of basic
block or in the upper block relatively.
This should improve compile time for the very big basic blocks.
Differential Revision: https://reviews.llvm.org/D99266
Unswitching a loop on a non-trivial divergent branch is expensive
since it serializes the execution of both version of the
loop. But identifying a divergent branch needs divergence analysis,
which is a function level analysis.
The legacy pass manager handles this dependency by isolating such a
loop transform and rerunning the required function analyses. This
functionality is currently missing in the new pass manager, and there
is no safe way for the SimpleLoopUnswitch pass to depend on
DivergenceAnalysis. So we conservatively assume that all non-trivial
branches are divergent if the target has divergence.
Reviewed By: tra
Differential Revision: https://reviews.llvm.org/D98958
This is yet another attempt to fix tightlyNested().
Add checks in tightlyNested() for the inner loop exit block,
such that 1) if there is control-flow divergence in between the inner
loop exit block and the outer loop latch, or 2) if the inner loop exit
block contains unsafe instructions, tightlyNested() returns false.
The reasoning behind is that after interchange, the original inner loop
exit block, which was part of the outer loop, would be put into the new
inner loop, and will be executed different number of times before and
after interchange. Thus it should be dealt with appropriately.
Reviewed By: Whitney
Differential Revision: https://reviews.llvm.org/D98263
Roman Lebedev